PHOTO

Grows to about 15mm long. Reported to feed on hydroids Eudendrium ramosum but in deeper water it is found eating Halecium articulosum and Clytia johnstoni.

Comparison from Terry Gosliner message below: 'The main external characteristics for differentiating F. gracilis from F. verrucosa is that the cerata are more distinctly arranged in rows in F. gracilis and there is a more prominent vestige of a notal brim in F. gracilis. Also F. gracilis has a sort of notched head between the junction of the oral tentacles and more elongate anterior margins of the foot'.